Railway elevator for transporting material up an incline



July 12, 1966 L. M. SHERIDAN RAILWAY ELEVATOR FOR TRANSPORTING MATERIAL UP AN INCLINE Filed Sept. 25, 1964 5 Sheets-Sheet l INVENTOR. LESLIE M SHERIDAN BUCKHORN BLORE KLARQUIST a. SPARKMAN ATTOR NEYS July 12, 1966 M. SHERIDAN 3,260,352

RAILWAY ELEVATOR FOR TRANSPORTING MATERIAL UP AN INCLINE Filed Sept. 25, 1964 5 Sheets-Sheet 2 22A e 4A 22A 22A H H H I] H lil III N I] 65 v INVENTOR. LESLIE M. SHERIDAN BUCKHORN,BLORE,KLARQU1ST & SPARKMAN ATTORNEYS y 2, 1966 L. M. SHERIDAN 3,260,352

RAILWAY ELEVATOR FOR TRANSPORTING MATERIAL UP AN INCLINE Filed Sept. 25, 1964 5 Sheets-Sheet 5 LESLIE M. SHER/DA/V INVENTOR. 19)

BUC/(HORN, BLORE, KLAROU/ST a SPAR/(MAN ATTORNEYS United States Patent 3,260,352 RAILWAY ELEVATOR FtUR TRANSPORTENG MATERIAL UP AN HNCLINE Lesiie M. Sheridan, 13 Chicago St., Butte, Mont. lFiied Sept. 25, 1964, Ser. No. 399,240 ill; (Claims. (Cl. 198-1l4lt)) The subject matter of the present invention relates generally to transportation devices for bulk material, and in particular to a railway elevator including an endless train of interconnected bucket containers which are moved on wheels along an inclined track by a single drive system, or a plurality of overlapping drive systems and means for transferring the containers from one drive system to another.

The bucket elevator railway of the present invention is especially useful in open pit mining to transport the mined ore over great vertical distances from the bottom of the pit up an incline to the top of such pit, or to some other elevated position, where the ore can be loaded into trucks for further transportation. This elevator eliminates the necessity of providing and maintaining a roadway down the side walls of the pit sufficient to enable trucks to travel to the bottom of the pit for loading and to haul the ore back to the top of such pit, and is much faster than attempting to transport the ore out of the pit by means of such trucks. However, the elevator may also be used over shorter distances to feed material at :a fast rate to blast furnaces in steel mills, or the like.

The bucket elevator of the present invention has several advantages over conventional bucket elevators due to the fact that it employs lost motion connections between at least some of the buckets which reduce the tension in the train of buckets and uses tracks to distribute the load of the bucket train between the track and drive means. In addition, one embodiment of the present elevator employs several overlapping endless drive systems. This allows the present bucket elevator to carry heavier loads at faster speeds up longer vertical distances than conventional bucket elevators having components of the same size. There is less shock transmitted to the bucket train at the upper and lower ends of the elevator because the train travels around a semicircular track portion at such ends, instead of around a chain sprocket as in conventional bucket elevators. The lost motion connections between bucket links compensate for any tendency of the bucket train to elongate because of wear so that no take up adjustment is required. Also, the lost motion connections compensate for any differences in pitch length between the bucket links or between the drive chain links caused by manufacturing tolerances or differential wear so that such differences do not prevent the bucket hooks from properly engaging the drive chains. Furthermore, the lost motion connections reduce the shock transmitted to the bucket hooks and the drive system when the hooks engage such drive system because due to the slack in such connections at the beginning of the drive system, the weight of only one bucket is picked up :at a time by the drive system. The weight of the next following bucket in the group is not picked up until the drive chain moves a few inches forward from the position of initial engagement with the attachment hooks of such group.

One embodiment of the bucket elevator of the present invention employs the lost motion connections between bucket containers to enable the containers to be transferred from one drive system to another without breaking the connection between such containers. This allows different groups of bucket containers, separated by sets of hooks attached to such containers for engagement with the drive systems, to be effectively driven by diiferent drive systems so that the total force exerted on each one of the plurality drive systems is substantially less than that which would be exerted on a conventional single drive system. Heretofore, when material was to be transported up a steep incline for a long distance, it was necessary to provide several intermediate reload station between conventional bucket elevators or conveyor systems, because it was not practical to make one large conventional conveyor system which was capable of transporting a heavy load over this great a distance. The present bucket elevator will accomplish this with a single drive system over a distance of about 200 to 400 feet without the need for reload stations since there there is less tension in the train of buckets and less load carried by the drive means. However, when a plurality of overlapping, standard size drive systems are employed to distribute the load between such drive systems, the present elevator is capable of transporting 40 tons of ore per minute up an incline of for a distance of 600 feet or more. In addition, the present bucket elevator is of a simple and reliable construction which is inexpensive to manufacture and requires little maintenance.

Therefore, one object of the present invention is to provide an improved device for transporting bulk materi-als.

Another object of the invention is to provide an improved railway elevator capable of transporting a heavier load up an incline over longer distances.

A further object of the present invention is to provide an improved bucket elevator capable of transporting bulk material up an incline continuously at a high rate of speed.

A still further object of the invention is to provide an improved elevator including a train of buckets connected together by lost motion connections and driven by a drive system up an incline along a track to decrease the tension in the bucket train and to decrease the load on the drive system in order to enable such elevator to be of a greater length.

Still another object of the invention is to provide an improved bucket elevator of simple and reliable construction which is relatively inexpensive to manufacture and requires less maintenance.

An additional object of the present invention is to provide an improved bucket elevator in which a plurality of overlapping drive systems are employed, along with a plurality of bucket containers which are fastened together by lost motion connections in order to transport heavy loads over greater vertical distances than conventional bucket elevators.

Additional objects and advantages of the present invention will be apparent from the following detailed description of a preferred embodiment thereof and from the attached drawings of which:

FIG. 1 is a side View of the preferred embodiment of the bucket elevator of the present invention with parts broken away for clarity;

FIG. 2 is an enlarged view of a portion of FIG. 1 with parts broken away for clarity;

FIG. 3 is a view taken along the line 33 of FIG. 2;

FIG. 4 is a schematic diagram of one embodiment of the conveyor drive mechanism employed in the bucket elevator of FIG. 1;

FIG. 4A is an enlarged view of a portion of the drive mechanism of FIG. 4 showing the position of the bucket hooks with respect to the chain links of such drive mechanism during transfer of the bucket containers from one conveyor system to another;

FIG. 5 is a schematic diagram of a portion of another embodiment of the drive mechanism of FIG. 4;

FIG. 6 is a schematic diagram of a portion of a third embodiment of the drive mechanism of FIG. 4;

FIG. 7 is a side view of another embodiment of the bucket elevator of the present invention;

FIG. 8 is an enlarged view of a portion of the bucket train of FIG. 7 adjacent the upper end of the down side of such train with parts broken away for clarity; and

FIG. 9 is a view similar to FIG. 8 of a portion of the bucket train adjacent the lower end of the down side of such train.

The bucket elevator of the present invention includes briefly a plurality of bucket containers 10 that are capable of holding large quantities of bulk material, such as crushed ore rock, which are mounted on wheels 12 and connected together in a manner hereafter described to form a continuous train of bucket containers. These containers are moved on their wheels around a closed path along an inclined track 14. The drive mechanism for the bucket containers 10 is in the form of a plurality of overlapping drive systems which may include a first drive system 16, a second drive system 18 and a third drive system 20. A plurality of sets of hooks 22 are attached to certain ones of the bucket containers 10 in order to divide such containers into groups which may each include four or five containers, and to connect each of such containers to one of the conveyor systems so that movement of the drive systems causes such bucket containers to move up the incline track 14.

A support frame 24 may be provided to support the track 14 and drive systems 16, 18 and above the ground on an incline of, for example, 45 degrees. This support frame may includes a plurality of posts 26 extending perpendicularly to a base member 28 and positioned in spaced relationship along the track 14. A plurality of beams 30 are attached between the posts 26, substantially parallel to the base 28 at positions slightly below the upper and lower portions of the track so that the rails forming such track may be supported on a plurality of support elements 32 similar to railroad ties which are attached to the top of the beams. Of course the support elements 32 do not extend completely across the track because the hooks 22 must travel between the track rails. The drive and idler sprockets 34 and 36, respectively, of the conveyor systems are also supported on the frame 24 by attachment of the opposite ends of their shafts to the beams 30.

The track 14 may be in the form of a pair of parallel metal rails which are supported on an incline to provide a continuous, closed path for the wheels 12 of the bucket containers. The track includes an upper portion 28 and a lower portion which extend in substantially straight parallel lines along opposite sides of the conveyor systems until they reach the lower end of the first conveyor system 16 and the upper end of the third conveyor system 20 where they curve inward toward each other to form semicircular end portions. The radius of curvature of each of the ends of the lower track portion 40 is greater than that of the ends of the upper track portion 38 and these ends overlap for a sufiicient distance to allow transfer of the wheels of the bucket containers from one track portion to another as such containers move around the corners of the track. Thus, as the empty bucket containers 10 travel by gravity down the lower track portion 40 in an upside-down position and reach the lower curved end of such track portion, the wheels of the bucket containers are guided around the corner of the track until such wheels are transferred to the curved lower end of the upper track portion 28. As the empty bucket containers turn to a right-side-up position and proceed up the track, the hooks 22 engage the drive chains of the first conveyor system 16 and such containers are filled with crushed ore rock or other load material 42 by passing beneath the usual loading device 44. This loading device may be in the form of an apron feeder having a discharge chute for directing the flow of material from such feeder into the bucket containers. The filled containers are driven up the inclined track by the drive system 16, 18 and 20 until they reach the upper end of track portion 28 which is curved to guide the wheels 12 of the containers around the corner of the track and to trasfer such wheels to the lower track portion 40. This causes the bucket containers to turn upside down and to discharge their contents into the receiving chute of the conventional transporting device 46 which carries the material away from the bucket elevator. It should be noted that after discharge of the load material 42, the bucket containers travel on down the lower track portion 40 by the force of gravity since the hooks 22 connecting them to the drive chains of the third drive system 20 are disengaged when such books pass over the drive sprockets 34 of the third drive system.

As shown in FIG. 2 and 3, each set of hooks 22 includes two pairs of hooks 22A and 22B which are mounted for pivoting about a shaft 48 that is rigidly secured at its ends between a pair of connecting links 50. The connecting links are attached to the sides of the bucket containers in a spaced parallel relationship so that they extend from the front to the rear of such containers. The hooks 22 are uniformly spaced along the shaft 48 by four spacer sleeves 52 which are mounted for rotation on such shaft and may be secured to the hooks intermediate ends of such hooks by welding or the like. One end of each of the hooks 22 is provided with an outwardly extending prong portion 54 which forms an angle of approximately with the main portion of such hook and is shaped to engage the connecting rollers of the drive chains. Each of the hooks 22 may also be provided with an outwardly extending arm portion 56 adjacent the spacer sleeve 52. A coil spring 58 is employed to resiliently urge each of the hooks toward the drive chains of the drive systems. This spring has one end secured in an opening through arm portion 56 and its other end secured through an opening in an L-shaped bar 60 which is suitably secured between the connecting links 50 thereof at a position slightly behind and above the hook shaft 48. Thus the coil spring 58 is under tension and exterts a force upon the hook 22 which pivots such hook clockwise, downward into engagement with the conveyor chain. The rear end of the hook 22 is provided with a stop surface 62 which engages the stop side of the L-shaped bar 60 remote from the spring 58 when the hook end portion 54 is not in engagement with a conveyor chain, such as when the bucket containers are riding on the lower track portion 40.

The connecting links 50 are each provided with an elongated slot 64 in the front end portion of such link through which the axle 66 of one pair of wheels 12 extends. This same wheel axle also extends through a smaller circular opening in the rear end portion of the next preceding connecting link. The rear end portion of the connecting links 50 is displaced slightly inward from the front end portion but extends parallel thereto in order to allow the front portions of consecutive links 50 to lie in substantially the same plane. Thus, the elongated slot 64 at the front end of each of the connecting links 50 provides a lost motion connection between the bucket containers 10. This lost motion connection allows slack movement between the bucket containers to enable the transfer of such containers from one drive system to another and to reduce the shock transmitted to the first drive system and the bucket books when the weight of the buckets is first applied to the drive system for the reasons mentioned above.

As shown in FIG. 4, the three drive systems 16, 18 and 20 are positioned so that they overlap with the drive chains of the first and second drive systems being positioned outside opposite ends of the second drive system 18. The two outside hooks 22A are positioned so that they can only engage the chain links in first and third drive systems 16 and 20, while the two inside hooks 22B are positioned so that they will only engage the chain links of the second drive system 18. Thus, the groups of bucket containers are first driven up the track 14 by the drive chains of drive system 16 due to engagement of the outer pair of hooks 22A with such chains. The inner pair of hooks 22B is disengaged until they reach the overlap portion of drive system 16 with drive system 18. As shown in FIG. 4A, the inner pair of hooks 22B is resiliently urged by springs 58 into position between the rollers on the chain links of the second conveyor system 18 after passing over the idler sprocket 36. However, the inner pair of hooks 2213 does not engage such rollers until after the outer pair of hooks 22A are disengaged from the first drive system 16 when they pass over the drive sprocket for such first drive system. In order to prevent the prong ends of the inner pair of hooks 22B from striking the top of the rollers of the chain of drive system 18 otr from otherwise engaging such rollers during the overlap portion of the first and second drive systems, the chains of such drive systems are driven out of phase with each other.

After the teeth of the drive sprocket 34 have pushed out the prongs of the outer pair of hooks 22A from engagement with the chains of the first drive system 16, the group of bucket containers moves back a short distance until the inner pair of hooks 22B engages the chains of the second drive system 18. This backward movement is cumulative in that the total amount of movement increases for each transfer of the bucket containers from one drive system to another due to the fact that such backward movements are added together. Thus, if the lost motion connection afiorded by slot 64 were not present to allow slack movement between the bucket containers, the connecting links 50 would eventually break.

As shown in FIG. 4, the drive sprocket 34 of each of the drive systems 16, 18 and 20 may be driven by a separate electric motor 68, 7t) and 72, respectively. The chains of the first drive system 16 may be shorter than that of the remaining systems so that the length of such drive system is appropriately equal to that of one group of bucket containers. The chains of the first drive system may be driven at a slightly greater speed than that of second drive system 18 in order to introduce slack into the lost motion connections between the bucket containers in the groups of buckets driven with the second drive system by pushing such bucket containers together with the group of buckets driven with such first drive system. This allows the chain of the third drive system 20 to move at substantially the same speed as that of the second drive system while permitting the transfer ;of bucket containers from the such second drive systems to the third drive system. Of course, the second and third drive systems may be driven at the same speed by connecting the drive sprocket of the second drive systems to the idler socket of the third drive system with appropriate gearing. In addition it is also possible to move the second drive system 18 at a faster speed than the first drive system 16 and at a slower speed than the third drive system 20 so that the hooks 22 of the bucket chain are transferred from one drive system to another before they reach the head sprockets of the drive systems to eliminate the wear on the sprocket teeth and hooks caused by camming action of such teeth removing the hooks from the drive chains. Also, more than three drive systems may be employed and the size of the groups of containers can also vary.

Another embodmient of the drive mechanism 16, 18 and 20 is shown in FIG. 5 which includes a pair of cables 74 and 76 connected together by a plurality of links 78 in place of each drive chain. The links are rigidly secured to the cables at the opposite ends of such links to prevent their movement on such cables. For a more positive drive these links 78 may be provided at regular intervals along such cables and toothed pulleys 80 and 82 may be provided in place of the drive sprocket 34 and idler sprocket 36, respectively. This may be ad vantageous since such a cable drive will provide greater tensile strength and may be more economical to operate than a chain drive.

Still another embodiment of the drive mechanism is shown in FIG. 6 which includes a single cable 84 having a plurality of lugs 86 attached thereto in place of each drive chain. The lugs 86 may be attached at regular intervals along the cable 84 and extend from both sides of such cable. Such lugs may be engaged by a modified hook 88 which has a Y-shaped prong end so that each hook is provided with a pair of hooked prongs adapted to fit on opposite sides of the cable 84 in engagement with the lug 86. In order to provide positive drive for the cable 84, it may be necessary to employ a pair of notched pulleys 9t} and 92 for the driver sprocket and idler sprocket, respectively.

Another embodiment of the bucket elevator or conveyor of the present invention is shown in FIGS. 7, 8 and 9 and is similar to that of FIG. 1 so that the same reference numerals have been used to identify corresponding parts. The bucket elevator of FIG. 7 differs from that previously described by using only a single drive system 94 which may be in the form of a double chain or cable, such as that shown in FIGS. 4, 5 and 6. This drive system is supported adjacent the up side of the bucket train between the upper and lower ends of such train so that the hooks 22A of the bucket train engage the upper side of the drive system in a similar manner to that shown in FIGS. 2 and 3. Of course, the second pair of hooks 22B can be eliminated when a single drive system is employed because they are no longer used to transfer the buckets to another drive system.

In the bucket elevator of FIG. 7, the lost motion connections provided by the slots 66 in links 58 still serve a function since they reduce the amount of tension in the bucket train. The Weight of the empty buckets 10 on the down side of the track 14 acts to pull the filled buckets located on the up side of the track between the drive system and the upper end of the track, around the upper end of such track and causes the links 50 of these buckets as well as those of the empty buckets on the upper portion of the track to be pulled apart so that the wheel axles 66 engage the leading end of the slots 64, as shown in FIG. 8. At the same time the weight of the empty buckets acts to push the empty buckets around the lower end of the track and to push the filled buckets up the track toward the drive chain 94, and causes the links of these buckets to be pushed together to move the wheel axles to the other end of the slots, as shown in FIG. 9. Thus, the bucket train is under compression at the lower portion of the train and is under tension at the upper portion of such train. This produces slack in the lost motion connections at the beginning of the drive system 94 to reduce the shock transmitted to such drive system and to the bucket hooks when the weight of the buckets is initially applied to the drive system, for the reasons discussed above. At the equilibrium position about midway of the down side of the track the bucket links change from the tension condition of FIG. 8 to the compression condition of FIG. 9. Therefore, the weight of only about one half of the empty buckets acts on the links under tension, and the stress of such tension is greatly reduced. In addition, the weight of the entire bucket train is distributed between the drive chain 94 and the track so that much of such weight is sup- .ported by the upper and lower ends of the track. As a result, the bucket elevator of FIG. 7 can carry heavier loads up greater vertical distances at faster rates of speed than conventional bucket elevators having components of comparable size.

It will be obvious to those having ordinary skill in the art that many changes may be made in the details of the preferred embodiment of the present invention without departing from the spirit of the invention. For example, lost motion connections need not be used between every pair of bucket links, and the hooks 22 could be replaced by lugs on the drive chains or cables which engage members on the bucket train for imparting movement to such train. Therefore, the scope of the invention should be determined by the following claims.

I claim:

1. Elevator apparatus, comprising:

a plurality of container members,

connection means for connecting said container members together in succession to enable movement of said container members together in a common closed path having upward and downward inclined portions and including lost motion connections to permit slack movement between at least some of said container members,

drive means supported along the upward inclined portion of said common path to provide a drive at the upward inclined portion for moving said container members along said common path, and

attachment means for releasably attaching said container members to said drive means so that the container members are moved upward attached to the drive means and are moved downward by gravity to produce slack in the lost motion connections at the beginning of the drive means.

2. Elevator apparatus, comprising:

a plurality of bucket container members,

connection means for connecting said container members together in an endless train to enable movement of said container members together in a common closed path of fixed length having upward and downward inclined portions and including lost motion connections between at least some of said container members to permit slack movement between said container members,

guide means for limiting the movement of said container members to said common path,

endless drive means supported along the upward inclined portion of said common path to provide a drive at said upward inclined portion for moving said container members along said common path, and

attachment means for releasably attaching said container members to said drive means so that the container members move upward attached to the drive means and move downward unattached to said drive means at least during the lower portion of the downward path to enable the production of slack in the lost motion connections at the beginning of the drive means.

3. Railway elevator, comprising:

a plurality of container members mounted on wheels,

connection means for connecting said container members together in a train to enable movement of said container members together in a common path of fixed length having an inclined portion and including slotted links as lost motion connections to permit slack movement between at least some of said container members,

a track having an inclined portion and supported adjacent said common path in position to engage the wheels of said container members,

drive means supported along the upper side of said inclined portion of said track to provide a drive for moving said container members along said common path, and

attachment means for releasably attaching said container members to said drive means so that the container members move upward attached to the drive means and move downward unattached to said drive means at least during the lower portion of the downward path to enable the production of slack in the lost motion connections at the beginning of the drive means.

4. Elevator apparatus, comprising:

a plurality of container members,

connection means for connecting said container members together in succession to enable movement of said container members together in a common path having an inclined portion and including lost motion connections between at least some of said container members to permit slack movement between said container members,

a plurality of drive means supported consecutively along said inclined portion of said common path for moving said container members along said common path, and

attachment means for releasably attaching said container members to said drive means at points spaced along said drive means so that some of said container members are driven by one of said drive means and other of said container members are driven by another of said drive means, and for transferring said container members from one drive means to another along said common path, said attachment means being of a type so that the container members move upward attached to the drive means and move downward unattached to said drive means at least during the lower portion of the downward path to enable the production of slack in the lost motion connections at the beginning of the drive means.

5. Elevator apparatus, comprising:

a plurality of container members,

connection means for connecting said container members together in a train to enable movement of said container members together in a common closed path of fixed length having an inclined portion and including lost motion connections between at least some of said container members to permit slack movement between said container members,

a plurality of separate endless drive systems supported consecutively along the upper side of said inclined portion of said common path for moving said container members along said common path, and

attachment means for releasably attaching said container members to said drive systems at points spaced along said drive systems so that some of said container members are driven by one of said drive sysems and other of said container members are driven by another of said drive systems, and for transferring said container members from one drive system to another at their overlapping portions, said attachment means being of a type so that the container members are moved upward attached to the drive means and are moved downward by gravity to produce slack in the lost motion connections at the beginning of the drive means.

6. Elevator apparatus, comprising:

a plurality of container members,

connection means for connecting said container members together in a train to enable movement of said container members together in a common closed path having an inclined portion and including lost motion connections between at least some of said container members to permit slack movement between said container members,

a plurality of separate drive means supported consecutively along said inclined portion of said common path to provide a substantially continuous drive for said container members along said inclined portion of said common path,

attachment means for releasably attaching said container members to said drive means at points spaced along said drive means so that some of said container members are driven by one of said drive means and other of said container members are simultaneously driven by another of said drive means, and for transferring said container members from one drive means to another of their overlapping portions to move said container members along said common path, and

power means for moving at least some of said drive means at different speeds to drive the container members so that said container members move along said common path without exceeding the limits of said slack movement between said container members.

7. A bucket elevator, comprising:

a plurality of bucket containers,

means for connecting said containers together in succession to enable movement of said containers in a common closed path having an inclined portion and including lost motion connections between at least some of said containers to permit slack movement between said containers,

:1 tnack having an inclined portion and supported to guide the movement of said containers along said common path,

a plurality of separate endless drive devices supported consecutively along at least said inclined portion of said track so that a portion of each of said drive devices overlaps a portion of the next consecutive conveyor device to provide a continuous drive for moving said containers along said track,

means for releasably attaching said containers to said dnive devices at points spaced along said drive devices so that some of said containers are driven by one of said drive devices and other of said containers are driven by another of said drive devices, and for transferring said containers from one drive device to another at their overlapping portions, and

means for moving a first one of said drive devices at the bottom of said track at a higher velocity than a second one of said drive devices to cause slack in the connection between containers driven by said second drive device to drive the containers so that said containers move from one conveyor device to another along said common path without exceeding the limits of said slack movement between said containers.

8. Railway elevator apparatus, comprising:

a plurality of material carriers connected together to form a train of carriers, each of said carriers including a container, 21 pair of support members attached to the opposite sides of said container so that said support members extend substantially parallel to each other from the front to the rear of said container, a shaft secured between said support members at one end thereof, and a pair of wheels secured to the opposite ends of said shaft for rotation, said carriers being connected together by an elongated slot through each of said support members adjacent the other end thereof through which the wheel shaft of the next consecutive carrier extends to form a lost motion connection which permits slack movement between said carriers,

a track of fixed length for said carriers having an in clined portion and including two pairs of rails which are positioned to engage the wheels of said carriers so that one of said pairs of rails forms an upper track portion and the other of said pairs of rails form a lower track portion to provide a common closed path for the movement of said carriers,

a plurality of separate endless drive systems supported adjacent said one pair of rails consecutively along said inclined portion of said common path, witha portion of each of said drive systems overlapping a portion of the next consecutive drive system to provide a continuous drive for said carriers along said upper track portion, and

means for releasably attaching certain of said carriers to said drive systems so that each of said drive systems drives at least one of said certain carriers, and for transferring said carriers from one drive system to another to move said train of carriers along said tracks.

9. Railway elevator apparatus, comprising: a plurality of material carriers connected together to form an endless train of carriers, each of said carriers including a bucket container, a pair of support members attached to the opposite sides of said container so that said support members extend substantially parallel to each other from the front to the rear of said container, a shaft secured between said support members at one end thereof, and a pair of wheels secured to the opposite ends of said shaft for rotation, said carriers being connected together by an elongated slot through each of said support members adjacent the other end thereof through which the wheels shaft of the next consecutive carr-ier extends to permit slack movement between said carriers,

an inclined track of fixed length for said carriers, in-

cluding two pairs of rails which are positioned to engage the wheels of said carriers so that one of said pairs of rails forms an upper track portion and the other of said pairs of rails form a lower track portion to provide a common closed path for the movement of said carriers,

a plurality of separate endless drive systems supported at the upper side of said track adjacent said one pair of rails consecutively along said common path, each of said drive systems including a drive chain, and a portion of each of said drive systems overlapping a portion of the next consecutive conveyor to provide a continuous drive for said carriers along said upper track portion, and a plurality of hooks secured to certain of said carriers which are spaced along the train of carriers to separate them into groups of carriers, at least one of the hooks on each of said certain carriers being positioned to engage one of said drive systems and at least one other of said hooks being positioned to engage the next of said drive systems so that different groups of carriers are driven by different drive systems.

10. Railway elevator apparatus, comprising: a plurality of material carriers connected together to form an endless train of carriers, each of said carriers including a bucket container, a pair of support members attached to the opposite sides of said container so that said support members extend substantially parallel to each other from the front to the rear of said container, a shaft secured between said support members at one end thereof, and a pair of wheels secured to the opposite ends of said shaft for rotation, said carriers being connected together into a train of carriers by an elongated slot through each of said support members adjacent the other end thereof through which the wheel shaft of the next consecutive carriers extends to permit slack movement between said carriers,

an inclined track of fixed length for said carriers, in-

cluding two pairs of rails having curved end portions which are positioned to engage the wheels of said carriers so that one of said pairs of rails forms an upper track portion and the other of said pairs of rails form a lower track portion to provide a common closed path for the movement of said carriers,

a plurality of separate endless drive systems supported a plurality of hook-s secured to certain of said carriers spaced along the train of carriers to separate them into groups of carriers, at least one pair of the hooks on each of said certain carriers being positioned to engage the chains of one of said drive systems and at least another pair of said hooks being positioned to engage the chains of the next of said drive systems,

spring means for resiliently urging said one pair of hooks into engagement with said drive chains when said hooks are properly positioned with respect to one of said drive systems, and for enabling the removal of said one pair of hooks from said drive chains after said other pair of hooks is in position to engage said next drive system in order to transfer said groups of carriers from one drive system to another, and

means for moving the chains of said drive systems in synchronism and for moving the lowest drive system :at a faster speed than the next drive system to cause slack in the connections between carriers to allow transfer of the groups of carriers from one drive system to another.

11. Railway apparatus, comprising:

a plurality of material carriers connected together to form a train of carriers, each of said carriers including a bucket container, a pair of support members attached to the opposite sides of said container so that said support members extend substantially parallel to each other from the front to the rear of said container, a shaft secured between said support members at one end thereof, and a pair of wheels secured to the opposite ends of said shaft for rotation, said carriers being connected together into a train of carriers by an elongated slot in each of said support members adjacent the other end thereof through which the wheel shaft of the next consecutive cari rer extends to permit slack movement between said carriers,

an inclined track for said carriers, including two pairs of rails which are positioned to engage the wheels of said carriers so that one of said pairs of rails forms an upper track portion and the other of said pairs of rails form a lower track portion to provide 12 a common closed path for the movement of said carriers.

a plurality of separate endless drive systems supported a plurality of hooks secured to certain of said carriers spaced along the train of carriers to separate them into groups of carriers, at least one of the hooks on each of said certain carriers being positioned to engage the lugs on one of the said conveyors and at least another of said hooks being positioned to engage the lugs on the next of said conveyors, and

spring means for resiliently urging said one hook into engagement with said lug when said hooks are properly positioned with respect to one of said drive systems, and for enabling the removal of said one hook from said one drive system after said other hook is in position to engage a lug on the next drive system in order to transfer the drive of said groups of carriers from one conveyor to another.

References Cited by the Examiner UNITED STATES PATENTS 253,896 2/ 1882 Smith 19814O X 2,918,020 12/1959 Henderson 198203 X FOREIGN PATENTS 440,183 1/ 1927 Germany. 849,015 9/ 1960 Great Britain.

EVON C. BLUNK, Primary Examiner.

EDWARD A. SROKA, Examiner. 

1. ELEVATOR APPARATUS, COMPRISING: A PLURALITY OF CONTAINER MEMBERS, CONNECTION MEANS FOR CONNECTING SAID CONTAINER MEMBERS TOGETHER IN SUCCESSION TO ENABLE MOVEMENT OF SAID CONTAINER MEMBERS TOGETHER IN A COMMON CLOSED PATH HAVING UPWARD AND DOWNWARD INCLINED PORTIONS AND INCLUDING LOST MOTION CONNECTIONS TO PERMIT SLACK MOVEMENTS BETWEEN AT LEAST SOME OF SAID CONTAINER MEMBERS, DRIVE MEANS SUPPORTED ALONG THE UPWARD INCLINED PORTION OF SAID COMMON PATH TO PROVIDE A DRIVE AT THE UPWARD INCLINED PORTION FOR MOVING SAID CONTAINER MEMBERS ALONG SAID COMMON PATH, AND ATTACHMENT MEANS FOR RELEASABLY ATTACHING SAID CONTAINER MEMBERS TO SAID DRIVE MEANS SO THAT THE CONTAINER MEMBERS ARE MOVED UPWARD ATTACHED TO THE DRIVE MEANS AND ARE MOVED DOWNWARD BY GRAVITY TO PRODUCE SLACK IN THE LOST MOTION CONNECTIONS AT THE BEGINNING OF THE DRIVE MEANS. 